In 1980, Bartlett ran for a seat in the U.S. Senate. In the Republican primary, he ranked fourth with just 7% of the vote, losing to incumbent U.S. Senator Charles Mathias, who won the primary with 55% of the vote.[3]

He ran again in the newly redrawn 6th congressional district and won the Republican primary with 42% of the vote.[7] Byron was upset by a somewhat more liberal Democrat, State Delegate Thomas Hattery, in the Democratic primary. Many conservative Democrats switched their support to Bartlett in November, as he defeated Hattery 54%–46%.[4][8]

1994–2006

During this time period, he never won re-election with less than 56% of the vote.

According to the Frederick News-Post, Bartlett had under-reported property sales by over $1 million since 2004 on his official financial disclosure forms, and made $299,000 in unreported loans in order to sell his daughter's home, over which he exercised power of attorney. Bartlett said that the under-reporting was an oversight and that he was a “bit player” in the real estate transactions.[9]

As the lone Republican in Maryland's congressional delegation, Bartlett won reelection in 2010 at the age of 84.[10] On June 1, 2009, Democrat and Iraq war veteran Andrew Duck formally announced a campaign for Congressman Bartlett's seat.[11]

Bartlett's district was significantly altered in redistricting plans released in October 2011, which was described as gerrymandering.[1][12]The Washington Post reported that the new district lines shifted the district slightly to the south, adding some heavily Democratic territory closer to Washington DC.[13]

When fellow Congressman Todd Akin made inappropriate comments about female biology, Bartlett immediately repudiated them, adding "“There is no room in politics for these types of statements...As a human physiologist I know there is no scientific backing to Todd’s claims.”[16] He said his view on abortion exceptions has been "[T]he same for twenty years. I’m pro-life, with exceptions for the life of the mother, rape and incest...I’m so avidly pro-life I’m against corporal punishment”, later adding that a very small proportion of abortions are a result of rape; however, in 2001 Bartlett had supported a constitutional amendment which did not include the rape and incest exceptions.[17] "The Maryland Democratic Party went after Bartlett", trying to connect Todd Akin's comments to Bartlett.[18]

Bartlett was heavily defeated in the general election by Delaney, taking only 38 percent of the vote to Delaney's 59 percent.[19]

Press reports indicate that Bartlett’s Political Action Committee is named Because All Responsible Taxpayers Like Every Truth Told PAC, or BARTLETT PAC for short.[23]

Press reports indicate Bartlett was instrumental in arranging House hearings on the dangers of an electromagnetic pulse attack on the United States.[24]

Bartlett is against the Senate bill to fund the United States Postal Service with an additional 33 billion dollars, calling it an "irresponsible bailout"—though he does claim to support "... maintaining next day delivery standards in rural areas that would keep the Cumberland mail processing facility open."[25]

Bartlett believes in the geologic theory of Peak Oil, and predicts that "the end of cheap oil and natural gas is coming and coming fast" as increasing global demand for energy overwhelms production.[26] In 2005, Bartlett established the Congressional Peak Oil Caucus with Rep. Tom Udall of New Mexico. Bartlett has argued that federal revenues from offshore oil and gas production should be invested in developing renewable energies.[27]

At a town hall meeting in September 2012, Bartlett claimed that federal student loans were unconstitutional and that disregarding the Constitution was a "very slippery slope" towards an event like the Holocaust. Bartlett later apologized for his remarks.[28]

Bartlett and his wife Ellen have 10 children (of whom one, Joseph R. Bartlett, is a former member of the Maryland House of Delegates), 17 grandchildren, and 2 great-grandchildren.[29] Following his defeat for re-election, Bartlett and his wife decided to live "off-the-grid" in the West Virginia mountains. Their cabin is devoid of outside electricity, phone service, or municipal plumbing. Bartlett currently works as a senior consultant for Lineage Technologies, a cyber security group that seeks to protect supply chains.[1]